A facility using recently developed automation methods will be operated and further improved to carry out scale genetic and physiological studies of bacteria, yeasts, and animal cells grown in tissue culture. Using recently constructed automatic materials handling equipment, photographic equipment and computer directed pattern recognition technique, this facility will be operated as a national research resource to carry out a program of biomedical research and development directed by scientists from a number of different laboratories. By automatic examination of up to 10 to the 8th power colonies in a batch, rare mutants will be isolated and partially characterized, mutagenic effects of chemical and physical agents will be measured even at low doses, and genetic recombination frequencies will be measured accurately for mapping purposes. Mutants for detailed study of DNA synthesis in E. coli and B. subtilis will be isolated and partially characterized. Mutants of E. coli, S. typhimurium, Saccharomyces cerevisiae will be isolated for study of biosynthetic and degradative pathways and for mechanisms of genetic recombination of physiological control. Genetic maps of E. coli, S. cerevisiae and some mammalian cell types will be enlarged. Feasibility studies of automatic recognition of bacterial and other pathogens in medical and public health applications will be extended. Mutagenic effects of food additives and other environmental chemicals will be tested in several bacterial, yeast and animal cell systems. Carcinogenic effects of chemical and physical agents including ionizing radiation will be examined using animal cells. Interactions of hormones and other agents with tumor cells grown in tissue culture will be examined to investigate the biochemical mechanism of the interactions and to test possible antineoplastic effects of a variety of substances. Mutant tumor cells sensitive to some agents and resistant to others will be isolated for further study. Screening programs may be undertaken when feasible for mutagens, carcinogens, antineoplastic agents and effects of low doses of mutagens and ionizing radiation. Additional technical development will be carried out as necessary.